An example of working machines having an electric motor as a drive source is a electric brush cutter which mows grasses, etc. The electric brush cutter has a lower running cost than that of an engine-driven brush cutter which uses a fuel. Moreover, because the performance of motors is being improved, electric brush cutters become widespread more and more.
Some electric motors have a rotor having a printed-wiring board. For example, Patent Literature 1 discloses a discoidal rotor comprising a stacked body of a commutator disk having a conductor pattern of a commutator formed thereon and a coil disk having a conductor pattern of a coil formed thereon. Most of such electric motors are small and have a flat shape, and in addition, have a low vibration level and a low noise level, and attract attention as a drive source for various kinds of working machines.